|
|
Joined: Feb 2007
Posts: 437 Likes: 1
Backyard Mechanic
|
OP
Backyard Mechanic
Joined: Feb 2007
Posts: 437 Likes: 1 |
What pressure should the fuel pump be developing for an original 1931?
Paul
If it isn't broken, fiddle with it anyway so you have something to repair.
1931 Deluxe Sport Roadster
1953 BelAir 4 dr. Sedan
1965 Chevy II Nova SS
|
|
|
|
|
Joined: Nov 2001
Posts: 19,758 Likes: 64
ChatMaster - 15,000
|
|
ChatMaster - 15,000
Joined: Nov 2001
Posts: 19,758 Likes: 64 |
About 1 psig on the fuel pump pressure. If above 2-2.5 psig it will overcome the needle/seat.
How Sweet the roar of a Chevy four!
|
|
|
|
|
Joined: Feb 2007
Posts: 437 Likes: 1
Backyard Mechanic
|
|
OP
Backyard Mechanic
Joined: Feb 2007
Posts: 437 Likes: 1 |
Thanks for the information. I want to put in a flow thru electric pump to overcome hard start and vapour locks caused by ethanol gas. Can't buy ethanol free in Ontario anymore.
Paul
If it isn't broken, fiddle with it anyway so you have something to repair.
1931 Deluxe Sport Roadster
1953 BelAir 4 dr. Sedan
1965 Chevy II Nova SS
|
|
|
|
|
Joined: May 2012
Posts: 4,374 Likes: 30
ChatMaster - 4,000
|
|
ChatMaster - 4,000
Joined: May 2012
Posts: 4,374 Likes: 30 |
i can only get ethanol gas here, and i have been using the StaBil360 in my fuel. fires right up and runs great. no issue the last 2+ years of doing this. And summer here gets mid to upper 90F if not hotter. Mid Atlantic US
AACA - VCCA - Stovebolt - ChevyTalk
Love the Antique Chevrolet's from 1928-1932
The Beauty, Simplicity, History, and the Stories they Tell
|
|
|
|
|
Joined: Jan 2022
Posts: 56 Likes: 3
Shade Tree Mechanic
|
|
Shade Tree Mechanic
Joined: Jan 2022
Posts: 56 Likes: 3 |
I have been considering installing an inline 6 volt fuel pump to help prime the fuel system on my 31 sport coupe. Has anyone considered pressurizing the gas tank with a pound or so with a hand air pump to prime the carb? I have also thought about installing a hand pump ball (the one used on outboard motors). Any input??????
|
|
|
|
|
Joined: Apr 2010
Posts: 734 Likes: 14
Oil Can Mechanic
|
|
Oil Can Mechanic
Joined: Apr 2010
Posts: 734 Likes: 14 |
Hello,
If 1 psi fuel pressure is normal for a 1931 Chevy Six and higher fuel pressure may overcome the needle/seat and flood the carb, wouldn't installing a constant electric fuel pump add to the flooding? Can anyone advise concerning the workings of the mechanical fuel pump? If an electric fuel pump is installed before the mechanical fuel pump (assuring electric pump fuel from fuel tank), will the mechanical fuel pump only supply designed fuel pressure to the carb or will the electric fuel pump override the mechanical fuel pump with a different psi to the carb? Will increasing fuel pressure override vapor lock and where is vapor lock most likely to be located. Are there not fuel line wrappings available to prevent vapor lock? Inquiring 1931 owner wants to know.
|
|
|
|
|
Joined: May 2012
Posts: 4,374 Likes: 30
ChatMaster - 4,000
|
|
ChatMaster - 4,000
Joined: May 2012
Posts: 4,374 Likes: 30 |
AACA - VCCA - Stovebolt - ChevyTalk
Love the Antique Chevrolet's from 1928-1932
The Beauty, Simplicity, History, and the Stories they Tell
|
|
|
|
|
Joined: Jul 2008
Posts: 1,896 Likes: 28
ChatMaster - 1,500
|
|
ChatMaster - 1,500
Joined: Jul 2008
Posts: 1,896 Likes: 28 |
Interesting discussion. Is a fuel pressure regulator required when you are just using the electric pump during a vapor lock condition?
Thanks
Dave
|
|
|
|
|
Joined: Apr 2010
Posts: 734 Likes: 14
Oil Can Mechanic
|
|
Oil Can Mechanic
Joined: Apr 2010
Posts: 734 Likes: 14 |
Hello,
When the stock 1931 Chevy mechanical fuel pump (pumps diaphragm) draws in non-pressurized fuel from the fuel tank, I believe that as the diaphragm pushes its full amount to the carb, then that should be the maximum psi developed. Now, if an electric fuel pump is installed between the fuel tank and the mechanical fuel pump, will there be a different psi at the carb? If so, how?
|
|
|
|
|
Joined: Dec 2007
Posts: 4,024 Likes: 99
ChatMaster - 4,000
|
|
ChatMaster - 4,000
Joined: Dec 2007
Posts: 4,024 Likes: 99 |
Interesting thread. One thought I had was whether the higher electric pump pressure would work against the intake stoke of the diaphragm or unseat the check valves.
I have another more modern classic car with an inline electric booster pump. It generates maybe 5 or 6 psi and will not overcome the carburetor float inlet valves. However the mechanical pump in that car generates about 4 psi. I only use the electric pump to fill the float bowls after the car has been sitting a few days. You can actually hear a change in the pump operating noise when the float bowls are full.
One factor is to make sure the pump you choose allows the mechanical pump to pull through it. Some electric fuel pumps are not designed to handle a “pull”.
Rusty
VCCA #44680
|
|
|
|
|
